Pipe or tube mill



Jan. 31, 1939.

I s'. FINDLAL'ER 2,145,588

PIPE OR TUBE MILL Filed June 8, 1937 4 Sheets-Sheet 1 S. F'INDLATER Jan.31, 1939.

PIPE OR TUBE MILL 4 Sheets-Sheet 2 Filed June 8, 1937 L INVENTOR.57El/EN5ON f7/v0L 47-53 Jan. 31, 19 39. 5 F|NDLATER 2,145,588

PIPE OR TUBE MILL Filed June 8, 1937 4 Sheets-Sheet 3 INVENTOR.STEVENSON HNDLAW'EE H/5 A TTORNEYS.

Patented Jan. 31, 1939 UNITED STATES PATENT OFFICE to National TubeCompany,,

New Jersey a corporation of Application June}, 1937, Serial No. 147,12'l

Claims.

This invention relates to pipe or tube mills and more particularly tothe handling of the mandrel employed therein.

In order to maintain a substantial. commercial 5 yield from a pipe ortube mill, the work-piece must be completely rolled in a minimumof-time. This, of course, requires the rapid withdrawal andrepositioning of the mandrel bar. That is to say, after the work-piecehas been rolled and is telescoped over the mandrel bar, the latter mustbe completely withdrawn from within the work-piece, which is thenremovedfrom the outlet bed of the mill, after which the mandrel bar isreturned to its original position.

On very large mills, for instance those which produce work-pieces oftwenty inches in diameter, the mandrel bar and mandrel bar carriageweigh over sixteen thousand pounds and are moved into position at therate of approximately five hundred feet per minute. -When a thin wallwork-piece is being produced, the plug on the mandrel bar must bepositioned very close to'the metal-workingrolls of the mill,'and ifpermitted to over-run its true position will occasion considerabledamage to the metal-working rolls and numerous other parts of the mill.

It is among the objects of the present invention tooperate a pipe ortube mill in a manner which is not only rapid but which also eliminatesdamage to the component parts thereof.

Another object is to provide an inexpensive and efllcient apparatuswhich may be installed on pipe or tube mills of existing design tofunction in the manner previously mentioned.

35 The foregoing and further objects will be apparent after referring tothe drawings, in which:

Figure 1 is aplan of a conventional pipe or tube mill which employscone-shaped metal-working to s.

o Figure 2 is a plan of the mill of Figure 1 on a smaller scale anddisclosing fragmentarily the outlet bed thereof.

Figure 3 is a view similar to Figure2 but dis-- a closing some of theelements of the pipe or tube mill in a different position.

Figure 4 is a view similar to Figure 1 but disclosing a mandrel bar anda mandrel plug carried thereby in the usual over-run position, whichoccasions the injurious results previously men- 50 tioned.

Figure 5 is a fragmentary sectional elevation of the mandrel barcarriage and its operating devices.

Figure 6 is a plan of one form of apparatus of 55 the present invention,

Figure 7 is a sectional view on the line VII-VII of Figure 6.

Flgure,8 is a wiring diagram.

. Figures 9, 10, 11, 12 and 13 are details of control switches. 5Referring more particularly to the drawings,- the numerals 2 and 3designate a pair of coneshaped metal-working rolls toward which there isextended a compression mandrel bar 4 carrying a mandrel plug 5 which isdisposed intermediate the metal-working rolls. After a pipe or tube hasbeen completely rolled between the metal-working rolls 2 and 3 and theintermediately disposed mandrel plug 5, and has moved onto the mandrelbar 4; it is removed from the mill by withdrawing 15 the mandrel bar andtransferring the pipe or tube by the usual kick-oil arms (not shown), toa conveniently disposed skidway 6. According to conventional practice,the mandrel bar 4 is suitably attached to a mandrel bar carriage 8 whichrides on an elongated frame 9 that forms part of the outlet bed of themill.

The outlet bedis provided with a pair of substantially spaced groovedpulleys Ill and H, the latter of which is driven by a motor l2. A cableI3 is strung between the rollers I0 and It and connected at its ends tothe mandrel bar carriage 8. Thus, by driving the motor i2, the man-,drel bar carriage 8, and the mandrel bar 4, are moved toward and awayfrom the mill, for ,the

purpose previously mentioned. Referring to Figures 6 and 7 of thedrawings, the metal working roll 3 is shown as provided with a shaft I4which extends toward an adjacently disposed frame l5. This frame l5carries a pair of aligned bearings I ,6, in which there is iournaled aninternally screw-threaded sleeve or nut ll: This internallyscrew-threaded sleeve or nut l'l carries an externally screw-threadedshaft l8 which is connected to the shaft ll of 40 the roll 3 by means ofa suitable slip-coupling 19. The shaft H has a large gear 20 securedthereto which is driven from a suitably rotated adjacently disposedshaft 22 by means of a wide pinion gear 2| which is secured to the shaft22.v The nature of the slip-coupling I9 is such that the gears 20 and 2|are rotated to drive the metal-working roll 3 without imparting rotationto the externally screw-threaded shaft [8. A worm-gear 23 is mounted onand secured to the internally screw-threaded sleeve or nut ll. A shaft24 is suitably journaled on the frame I5 and has secured thereto a worm25 which engages the worm-gear 23 on the sleeve or nut ll. Areversibleelectric motor 29. is mounted on the u All frame I5 andprovided with an elongated drive shaft 30 to the extended end of whichthere is secured a pinion 3i which meshes with a large gear 2'I, thelatter being secured to the shaft 24. The motor 29 is provided with aconventional magnetic brake 34.

According to the foregoing construction, it will be seen that thedriving of the elongated drive shaft 30 of the motor 29 in alternatedirections will move the roll 2 toward and away from the roll 3 and themandrel plug 5, when the latter is occupying its metal-working position.

Referring to Figure 5, a vertical support 50 is disposed over the outletbed of the pipe or tube mill adjacent the mandrel bar carriage 9 whenthe latter is in its forward position. This vertical support 50 carriesa shaft 5I on which there is mounted a pivotable latch 52 having aflattened portion 59 on its extended end. The upper surface of themandrel bar carriage 8 is provided with an abutment plate 54 having aflattened face 55.

At one side of the upper end of the vertical support 50 there isdisposed a fluid-actuated cylinder 59, the piston of which is pivotallyconnected, as at 57, to a crank-arm 58 which is secured to the shaft 5i.Thus, it will be seen that the energization of the fluid-actuatedcylinder 56 will rotate the shaft 5| so as to raise the latch 50 in suchmanner as to present its flattened portion 53 for contact with theflattened face 55 of the abutment plate 54 on the mandrel bar carriage8.

The vertical support 50 maybe provided with suitable adjusting mechanism(not shown) for varying the position of the mandrel bar carriage 0 withrespect to the metal-working rolls 2 and 3 in order to provide forchanges in the wall thickness of the pipe or tube A.

Any suitable and conventional electric wiring circuits, includingcontrol devices, are provided for the motor 29 and the magnetic brake34.

In operation, a tube A, which is shown as having previously beenpierced, is introduced between the metal-working rolls 2 and 3 formovement over. the mandrel plug 5 on the forward end of the mandrel bar4. The tube A is moved over the mandrel plug 5 and mandrel bar 4 by thehelical advancing action of the metal-working rolls 2 and 3. As soon asthe trailing end of the tube A has moved over the mandrel plug 5 andonto the mandrel bar 4, the motor 29 is suitably actuated (automaticallyor otherwise) to withdraw the metal-working roll 3 with respect to themetal-working roll 2.

As soon as the metal-working roll 3 has been Withdrawn a predetermineddistance, the motor 29 and magnetic brake 24 are deenergized, therebyapplying the latter. The mandrel bar I and mandrel plug 5,simultaneously with the withdrawal of the metal-working roll 9, afterthe energization of the fluid-actuated cylinder 56, are movedlongitudinally of the outlet bed of the tube mill and away from therolls 2 and 3 by the energization of the motor I2 to such an extent asto withdraw the mandrel bar 4 from the interior of tube A and to permitremoval of the mandrel plug 5. The tube A is removed from the outlet bedof the mill by the usual kick-off devices (not shown). The direction ofrotation of the motor I 2 is then reversed to move the mandrel bar 4 andthe latch 52. The magnetic brake 34 is then energized to release theshaft of the motor 29, and the latter driven in a direction of rotationwhich is reverse to that previously described. This reverse direction ofrotation of the motor 29 is decidedly rapid and likewise rapidly movesthe metal-working roll 3 toward the metal-working roll 2. As soon as theroll 3 has advanced to a position which is adjacent its metal-workingposition in the mill, a limit switch is operated which, in turn, verymaterially retards, but does not stop, the rotation of the motor 29. Themotor 29 continues its rotation in this retarded fashion until themetal-working roll 3 reaches its exact true metal-working position inthe mill, at which time a limit switch deenergizes the motor 29 and themagnetic brake 34, thereby applying the latter.

The metal-working rolls 2 and 3 are, at this stage of the operation,ready to receive the next pipe or tube A and advance the same helicallyover the mandrel bar 4 and mandrel plug 5 which are now returned totheir initial metal-working positions in the manner previouslydescribed.

Referring to Figure 8 of the drawings, I have illustrated one form ofelectrical circuit which may be utilized to operate the devices of theinvention in the manner previously described. In

this diagram the numerals I00 and I02 designate,

a pair of suitable power lines carrying normal voltage; such as 220volts. In order to satisfactorily control the operation of thereversible motor 29, it is connected to the power lines I00 and I02through a manually operable switch I03 by a line I04 and includes in itscircuit contacts I05"- and I05 and I06 and MW, which are operated bycoils I05 and I06, respectively, in a manner to be later described. Theseries field of the reversible motor 29 is designated in the line I04 at29 The magnetic brake 34 for the reversible motor 29 is also connectedin series in this line I 04, whereby it will be energized during thepassage of current therethrough;

A line I I0 is connected between the power lines I00 and I02 andincludes in its circuit contacts H2 H4 and H0 which form part of limitswitches II2, II4 and H6, respectively; together with coil I06 whichoperates the contacts I06 and I00 of the motor 29. A line I20 isconnected to the line II 0 between the contact 2 of the limit switch H2and the power line I00, and to the line IIO between the coil I06 and thepower line I 02. This line I20 has included in its circuit contacts I I2and 4 and H6 which also form part of the limit switches H2, H4 and H6,respectively; together with a coil I05 which operates the contacts I05and I05 of the motor 29.

Referring to Figure 9, the limit switch H2 is shown as comprising anoperating arm which is spring-biased into connection with the contactII2 but operable by contact with the lower part of the mandrel barcarriage 8, while the latter is in its forward position, into connectionwith the contact H2. The limit switch H4 is shown as comprising anoperating arm secured to the shaft 5| on the upper part of the verticalsupport 50. The energization of the fluid cylinder 55 will move theoperating arm of the limit switch I I4 into connection with the contactI III and the deenergization of the fluid-cylinder 56 will permit thelatch 52 on the shaft 5| to drop by gravity.

and move the operating arm into connection with the contact I I4Referring to Figures 11, 12 and 13, the limit switch H6 is shown ascomprising a screw I30 which is secured to and rotates with the shaft33. This screw I30 carries a nut I32 which-is provided with a centrallydepending ing which rides in a guideway I33 formed by part of the frameI5. Each side of the nut I32 is provided with a stud I34 which carries apivotally mounted roller IIB. Each of the rollers III rides fora limiteddistance on a longitudinally adjustable contact strip which is mountedon, but suitably insulated from, the frame I5.. These contact stripsform contacts I I6 and H6 which operate in a manner to be laterdescribed. According to the embodiment illustrated, the rollers I I3will, when in extreme positions, connect either the contact I I6 or thecontact H6, and permit a limited range of travel of the nut I32 duringwhich both contacts will be connected.

While the mandrel bar carriage 3 is in its forward position, thecontacts H2 and H4 of the limit switches H2 and H4, respectively, areclosed, but the nut I 32 of the limit switch II3 occupies its extremeinward position on the shaft I30, thereby breaking connection with thecontact H6 but continuing connection with the contact I I6. Therefore,the operating coil. I06 is now deenergized, thereby opening the contactsI 06 and I06 of the reversible motor 23. The coil I05 is at this timedeenergized because the contacts II2 and H4 of the limit switches H2 andH4, respectively, are open. The foregoing position of elements isrepresented in the diagram of Figure 8 of the drawings.

As soon as the tube A has been completely pierced by the conjointoperation of the metalworking rolls 2 and 3 and the mandrel plug 5 onthe forward end of the mandrel bar 4, the operator of the mill operatesa suitable valve to fill the cylinder 56 with fluid under pressure,thereby raising the latch 52.

The raising of the latch 52 breaks the connec-,

tion of the limit switch II4 with its contact H4 and makes connectionwith its contact I I4. The operator then operates the reversing switch Ifor the reversible motor I2 to drive the same in such manner as towithdraw the mandrel bar carriage 0. This operation of the motor I2 iscontinued until the mandrel bar carriage 8 is in its extreme rearwardposition.

As soon as the mandrel bar carriage 0 begins its rearward movementcaused by the operation of the reversible motor I2, the contact II2 ofthe limit switch H2 is closed by its operating spring I I2 In view ofthe fact that the limit switches H4 and H6 are at this time alreadyconnected with their contacts H4 and H6, respectively, the coil I05 isenergized by the closing of the contact II2 of the limit switch II2, asjust described, to close the contacts I05 and I05 of the motor 23. Thisconnection of the motor 23 energizes, and therefore releases, themagnetic brake 34 and permits the former to withdraw the metalworkingroll 3 from the position it previously occupied. The extent of thismovement is short and determined by the distance required by the travelof the nut I32 to break the connection of the contact II6 with itscontacting roller H6. The breaking of the connection of the limit switchII6 with the contact II6 deenergizes the coil I05, thereby opening thecontacts I05 and I05 to deenergize the motor 23 and also the magneticbrake 34 which is then applied.

The foregoing operation of the devices included in the wiring diagram ofFigure 8 is entirely independent of the operation of the motor I2,which, as before stated, is operated to withdraw the mandrel barcarriage I to its extreme rearward position either automatically ormanually. When the mandrel bar carriage 8 is completely withdrawn, thereversible motor I2 is deenergized. The operator then operates the usualkick-off arms (not shown) to translate the tube A from the outlet bed ofthe mill whereupon it is permitted to roll over the skidway 6. Theoperator then restores the kick-off arms to their initial positions andoperates the reversing switch I25 to drive the reversible motor I2 insuch manner as to move the mandrel bar carriage 8 to its initialposition. The reversing switch I25 is then operated to deenergize thereversible motor I2. If desired, the operation of the reversible motorI2 may be regulated by suitable limit switches (not shown).

As soon as the mandrel bar carriage 8 arrives at its proximate initialposition, it operates the limit switch II2 to make connection with thecontact H2 and break connection with the contact H2". At this time thelatch 52 is either already in its lowermost position, or is then movedinto such position by exhausting the fluid from the fluid-cylinder 56,whereupon it is permitted by gravity to drop. The lowering of the latch52 operates the limit switch II4 to make connection 'with the contactH4". The limit switches H2 and H6 are in connection with the contacts H2and II 6, respectively. Therefore, the closing of the contact II4 of thelimit switch II4 now energizes the coil I06 which closes the contactsI06 and I06 of .the reversible motor 23. This energizes the motor 29 andalso the magnetic brake 34 which is then released. The motor 23 thenreturns the metal-working roll 3 to its initial position.

As soon as the metal-working roll 3 is restored to its exactly properinitial position, the now outwardly traveling nut I32 breaks theconnection of the limit switch II6 with the contact II6 but continuesits connection with the contact H6". The breaking of the connection ofthe limit switch II6 with the contact H6 deenergizes the coil I06,thereby opening the contacts I06 and I0Ii to deenergize the motor 26 andalso the magnetic brake 34 which is then applied.

The entire apparatus is thus set for another cycle of operation, whichis initiated after the passage of a succeeding tube A through the mill.

In my copending application, Serial No. 147,128, entitled Pipe or tubemills" and filed concurrently herewith, there is disclosed and claimedan apparatus which eliminates the overrunning of the plug on the mandrelbar, whereby its impact with the metal-working rolls of the mill isprevented. In said copending application this result is obtainedentirely by the control of the movement of the mandrel bar carriage.

While I have shown and described one specific embodiment of myinvention, it will be understood that I do not wish to be limitedexactly thereto, since various modifications may be made withoutdeparting from the scope of my invention, as defined by the followingclaims.

I claim:

.1. The method of making metallic pipes or tubes which include passing ametallic blank being position while the metal-working roll is withdrawn,and then returning the withdrawn metalworking roll to its metal-worlnngposition.

2. A pipe or tube mill comprising, in combination, at least a pair ofmetal-working rolls, a mandrel, means for moving said mandrel toward andaway from said metal-working rolls, releasable means for holding saidmandrel in its metal-working {position against the thrust of thework-piece, means for withdrawing one of said metal-working rolls fromits metal-working position, said withdrawing means being operable onlywhen said releasable mandrel holding means is in released position, andmeans for returning said metal-working roll to its metalworkingposition, said returning means being operable only when said releasablemandrel holding means'is in holding position.

3. Apipe or tube mill comprisingdn'combination, at least a pair ofmetal-working rolls, a mandrel, means for moving said mandrel toward andaway from said metal-working rolls, releasable means for holding saidmandrel in its metal-working position against the thrust of thework-piece, means dependent upon the position of said first named meansfor withdrawing one of said metalworking rolls from its metal-workingposition, said withdrawing means being operable only when saidreleasable mandrel holding means is in released position, and means glepe ndentupon amazes releasable means for holding said mandrel in itsmetal-working position against the thrust of the work-piece, meansoperable by said first namied means for withdrawing one of saidmetal-working rolls from its metal-working position, said withdrawingmeans being operable only when said releasable mandrel holding means isin released position, and means for returning said metalworking roll toits metal-working position, said returning means being operable onlywhen said releasable mandrel holding means is in holding position.

5. The method of making metallic pipes or tubes which includes passing ametallic blank between at least a pair of metal-working rolls and over amandrel, withdrawing the mandrel from the interior of the tubular blank,withdrawing at least one of the metal-working rolls from itsmetal-working position, returning the mandrel to its metal-workingposition while the metal-working roll is withdrawn, and then returningthe withdrawn metal-working roll to its metal-working position.

STEVENSON FINDLA'IER.

